United Kingdom, Sept. 29 -- Sylvester Stallone "wailed" with grief after the death of his son Sage.

The Hollywood action man was left devastated after his eldest child - who he shared with ex-wife Sasha Czack - died in 2012 at the age of 36 due to a heart condition and Stallone has confessed he felt overwhelmed with "pain and grief and guilt" as he dealt with the tragedy.

In an interview with The New York Times, Stallone recalled the moment he was told about his son's death in a phone call from his mother Jackie's third husband Dr Stephen Levine. Stallone said: "'I'll never forget, it was so cold: My mother's new husband, who I'd never even met, who was a doctor, called me and goes: 'Sly, he's gone. Sage - he's gone.' I went: 'Gone wher...